Expose sequence placement controls in the public API

internal/engine/records.go

@@ -197,6 +197,24 @@ type SourceInfo struct {
 	destinationUnresolved bool
 }
 
+// SourceInfoPlacementModeForFacade converts private placement evidence to its
+// root-owned numeric representation.
+func SourceInfoPlacementModeForFacade(source SourceInfo) uint8 {
+	return uint8(source.placementMode)
+}
+
+// SourceInfoDestinationUnresolvedForFacade returns the private fallback marker.
+func SourceInfoDestinationUnresolvedForFacade(source SourceInfo) bool {
+	return source.destinationUnresolved
+}
+
+// SourceInfoWithPlacement copies facade-owned source evidence into private fields.
+func SourceInfoWithPlacement(source SourceInfo, mode uint8, unresolved bool) SourceInfo {
+	source.placementMode = placementMode(mode)
+	source.destinationUnresolved = unresolved
+	return source
+}
+
 // SourceVersionCheck is a detached, public-safe record of a source-local
 // version declaration observed during an enabled load.
 type SourceVersionCheck struct {